For the past few months we have been hearing about how Ariel Sharon is going to set the permanent borders of Israel, change the political system to a Presidential one, change Israeli politics, etc.
Given the events of last night and this morning it is clear that he will be doing none of this and he may not even live out the day.
We should learn from this that a person can make all kinds of plans, but ultimately everything depends on Hashem. You can be the most powerful person in the country 1 minute and be struck powerless the next.
In addition we should all take a lesson from this and not put things off until tomorrow (I will learn more, do more mitzvos etc.), because tomorrow may never come.